Pine is better than cedar but it's still not ideal. Aspen is better than pine. I buy CareFresh for my rabbits' litter pans.
At issue are the aromatic hydrocarbons that woods release. They can cause problems, even cancer. There's also the
problem of the air bourne dust itself. I don't suggest keeping rabbits on wire or grates as it's bad on their feet. It's good
that the rabbit can't get to the litter but you can use a regular cat litter pan with CareFresh, straw, newspaper, etc. Some
buns will eat newspaper, and they can, of course, eat the hay. My buns don't eat CareFresh but, if your bun did, you
couldn't use that.
The hamster can use the pine shavings but the CareFresh would also work well for him.
Here is a web site with information about the various kinds of beddings and problems with them:http://www.aracnet.com/~seagull/faq/beddingfaq.html